Rotary piston fluid motor



June 12, 1962 F. GRELL ROTARY PISTON FLUID MOTOR 3 Sheets-Sheet 2 Filed April 1, 1959 Rank 6178/] INVENTOR.

June 12, 1962 F. GRELL 3,038,452

ROTARY PISTON FLUID MOTOR Filed April 1, 1959 3 Sheets-Sheet 5 Fig.8

Frank Gre/l mmvroza.

BY @Mdaia (yang .FMIF

United States Patent W 3,038,452 RQTARY PESTGN FLUID Grail, 3155 319th Ave. fir, Fort Dodge, Fiied Apr. l, 1%), See. No. 33,516 3 tliaims. {Ct Hi --95) This invention relates to a new and useful rotary piston fluid motor and more particularly to a fluid motor having a constant pressure area with a rotary piston mounted therein on a driveshaft with swinging vanes spaced about the periphery of the rotary piston engaging a stationary abutment block, inlet and outlet openings being provided at opposite ends of the abutment block.

The main object of this invention is to provide an improved rotary piston fluid motor having a minimum number of moving parts and therefore one which will be more dependable and require less maintenance.

A further object of this invention is to provide means for compensating for wear throughout the fluid motor wherever it may occur.

Another object, in accordance with the preceding object, is to provide an abutment block which may be adjusted in position so as to maintain the proper clearance between it and the outer periphery of the rotary piston.

Still another object is to provide a rotor with annular pressure seals on opposite sides thereof engaging the sides of the housing in which the rotor is journalled thereby confining the fluid under pressure to working space which is disposed between the outer periphery of the rotary piston and the casing.

A still further object is to provide a rotary piston fluid motor of the type having a stationary abutment block therein with two outlet openings, one being formed through a portion ofthe camming surface on the abutment block, and the other being formed through the casing a spaced distance from the abutment block, whereby at least one outlet opening will be out of registry with the swinging vane approaching the abutment block.

Another object, in accordance with the preceding objects is to secure dynamic balancing for the rotary piston despite the provision of notches in its periphery and pivoting vanes in the notches.

Still another object, in accordance with the preceding objects, is to secure more perfect exhausting of the work chamber by preventing back pressure to develop in advance of vane approaching the abutment block in the form of exhaust being trapped as the vane passes the main exhaust port.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein, like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the invention shown conveniently mounted upon support members;

FIGURE 2 is an enlarged horizontal sectional view of the invention taken substantially upon the plane indicated by the section line Z--2 of FIGURE 1;

FIGURE 3 is an enlarged side elevational view of the invention parts being broken away and shown in section;

FIGURE 4 is a vertical sectional detail View taken sub stantially upon the plane indicated by the section line 4-4 of FIGURE 1;

FIGURE 5 is an end elevational view of the invention as seen in FIGURE 1 with the front cover plate thereof being removed;

FIGURE 6 is an end elevational view of the invention similar to that of FIGURE 5 but with parts being broken away and shown in section;

FIGURE 7 is an exploded view of the abutment block showing the manner in which the roller is journalled theresa a- 5:2

Patented June 12, 1952 in, and how a shim may be used to compensate for Wear on the face of the abutment block adjacent the rotor; and

FIGURE 8 is an exploded detail view in perspective of a portion of a rotor showing the manner in which the swinging vane is pivotally secured thereto.

Referring now more particularly to the drawings, the numeral 1e generally designates the rotary piston fluid motor comprising the present invention which is shown mounted upon a suitable supporting frame 12 by means of mounting bolts 14. The fluid motor 10 comprises a drum-like casing 16 having a cylindrical chamber or recess 18 formed therein defining a rear wall 19 and cylindrical side walls 21 and a cover plate 20 comprising a closure for the cylindrical chamber 18. Journalled in casing 16 and extending through cover plate 2% is a driving shaft 22 which has keyed, or secured thereto in any convenient manner, a rotary piston 24 which is contained within chamber 18 and is concentric therewith. The rotary piston 24 is smaller in diameter than the cylindrical chamber 18 and defines an annular work chamber 26 therebetween. The cover plate 20 is secured to the casing 16 by threaded bolts 23 and threaded nuts 30. Rotary piston 24- is secured to shaft 22 by means of key 32 and has formed in its outer periphery notches 34 each having lugs 36 formed therein, see FIGURE 8. Mounted in each notch 34 is a swinging vane 38 which is bifurcated at its inner end as at 40 to receive lug 36. Formed through each of the lugs 36 and the bifurcated vanes 38 are apertures 42 which are registerable to slidingly receive pin 44. Secured in each notch 34- by any convenient means is a compression spring 46 which yieldingly urges each of the vanes 33 towards the closed position with the free ends thereof sliding engagement with the outer periphery of cylindrical chamber 18. Pin 44 is slightly shorter in length than the distance between the remote ends of the apertures 42 formed in each of the swinging vanes '38, and a sealing plug 48, which maybe constructed of leather or any like material, is received within the outer extremities of apertures 42 formed in each of the swinging vanes 33 so that a cushioning surface is provided between the ends of each of the pins 44 and the casing 16 and the cover plate 29 of the fluid motor it Rotary piston 24 is provided with annular pressure seals 5t constructed of any suitable material which are concentric therewith and secured to opposite sides thereof a spaced distance radially inwardly from notches 34.

With attention drawn now to FIGURE 6 of the drawings, an arcuate abutment block 52 is secured within work chamber 2s and to the concave wall thereof by means of mounting bolts 54 and lock nuts 56 so that its relative radial position in relation to rotary piston 24 may be adjusted. Mounting bolts 54 are inserted through apertures and threadediy engaged in threaded bores 6%? formed in abutment block 52.

Abutment block is provided with a smooth convex leading or abutment surface 62 and a smooth concave trainng or departure surface 6 3, the former being provided to cam each of the swinging vanes 3%) into a closed position whereby the latter will be received entirely within the corersponding notch 3 and the latter comprising abrupt departure surface which allows the complete opening of the swinging vane into a position with the free end in sliding engagement with the outer periphery of the work chamber 26 as the vanes 38 carried by the rotary piston 24 are moved into registry with the inlet port 6%, a part of the inlet port being formed through the trailing surface of the abutment block 52. The in let port 66 has a threaded outer portion in which a threaded inlet line 68 is engaged.

Formed through a portion of the leading surface 62 is an outlet port 7% which also extends through the casing 16 and has a threaded outer portion in which is threadedly secured a first outlet line '72. A second outlet line 74 is threadingly engaged in the outer portion of a second outlet port formed through casing in a spaced distance from the leading or can surface d2 of the abutment block 52. Journalled in the abutment block 52 and projecting slightly from the leading or cam surface 62 thereof into a work chamber 26 is a roller it; which serves to reduce the friction between the abutment block 52 and one of the swinging vanes 53 being cannned into a closed position within notch 34.

A roller bearing or any other suitable bearing 89 is provided at opposite ends of shaft 22., in the casing 16 and the cover plate iii. A cylindrical bearing cap 82 is provided for the rear end of shaft 22 and is secured to the casing 16 by means of threaded bolts passed through end plates 86 and threadediy engaged within casing 16. An annular seal 83 is provided between end plate 86 and bearing cap 82 and annular seal 9% is pro vided between bearing cap 32 and the casing it), see FIGURE 2. The roller bearing 3% secured about the forward end of the shaft 22 is received wi .in counter-- bore 92 formed in the front cover plate 2% and is retained therein by means of retaining plate 94- there being an oil seal 96 positioned between front cover plate as and retaining plate 9 With attention now drawn to FEGURES 5 7 or" the drawings, it will be seen that there is provided between the abutment block 52 and the casing 36 an arcuate shim 96 having a pair of end notches J3 and side notches Mil. The end notches 93 are registerable with outlet ports 66 and 7t and the side notches ltltl are registerable with threaded bores 6 and apertures 53. It is to be understood that the shim )6 is to be used only to compensate for excessive wear of the abutment blocl: 52 after prolonged use of the fluid motor fill, slight wear being compensated for by the adjustment of threaded bolts 54 and lock nuts 53.

The cover 2% is provided with an inwardly directed circular projection Hi2 which is complementary to and slidably received in cylindrical chamber 19 when the cover plate is secured in position upon the casing in. An annular shim we, see FEGURES 2, 3 and 4 is provided between the abutting surfaces of the cover plate and the casing 16 and may be varied in thickness to compensate for wear between the rotary piston 24 and the adjoining surface of the casing 16 and the it nt cover plate 2%. Further, it is to be understood that various interchangeable annular seals 33 and it; of varied thicknesses will be employed whereby further to compensate for wear between the rotary piston and the confronting surfaces of the casing 16 and the front cover plate 2%.

As will be noted by FEGURES 5 and 6 of the drawings, the swinging vanes 33 are entirely received within notches 34 when they are cammed into the open position by the abutment block 52, and have convex outer surfaces which are actually segments of the circular outer periphery of the rotary piston Further, the swinging vanes 38, when in the closed position, have rotated slightly less than 90 from an open position so that their swinging motion toward the closed position is limited by the sliding contact of the outer ends we thereof with the outer periphery of the work chamber 26. Thus, as wear occurs between the outer surface 1% of the swing vanes 3% and the outer periphery of the working chamber 26, the vanes 33 merely pivot through a greater are toward the position 96 rom the open position to automatically compensate for the wear between the outer wall of the working chamber 26 and the outer end of the swinging vanes 33.

In operation, with attention again drawn to FIGURE 6 of the drawings, as fluid under pressure enters the inlet port 66 through inlet line 63, pressure is applied to the trailing edge Illtl of the last swinging vane 33 to pass the abutment block 52. The trailing edge ill) of that swinging vane 38 then constitutes a piston head for the rotary piston 24- moving the latter in the direction indicated by the arrow effecting the rotation of the power take-off flange 166 secured to the projecting end of shaft The portion of the work chamber as then disposed between the swinging vane 38 which then acts as the piston head and the other swinging vane 38 constitutes a dead or idle chamber, while the portion of the work chamber as located in front of the outer swinging vane 38 constitutes an exhaust chamber. if the rotary piston 24- is in the position shown in FZGURE 6 of the drawings, the portion of the work chamber 26 disposed rearwardly of the vane 33 in the closed position comprises a pressure chamber, while the portion of the work charnber 26 disposed farwardly of that same vane comprises an exhaust chamber. When the rotary piston 24 is in this position, there is no dead chamber as there is only one swinging vane 33 in the closed position disposed between the inlet port 65 and the outlet ports "ill and 76.

With attention now drawn to FIGURE 5 of the drawings, the swinging vane 33 is now adjacent to the outlet port and the fluid contained in the work chamber 26 in advance of that vane is moved or pushed by the vane out the casing in by means of the exhaust ports it? and 76 formed thercthrough. As the swinging vane 33 moves into registry with the first exhaust port 76, it has a tendency to block this port which would necessarily cause a pressure build-up by fluid trapped in that portion of the work chamber 26 disposed between outlet port "/6 and the abutment block 52. However, with the provision of the second outlet port 7%, this pressure buildup is not allowed to form but is released since the fiuid may xit through outlet port '79. As the vane 33 moves past the outlet port 76 the dead chamber disposed therebehind then becomes an exhaust chamber and the fluid remaining in the work chamber between the swinging vane 33 and the abutment block is allowed to exit through outlet port '76. Actually, under working conditions at normal operating speeds, as a swinging vane 38 becomes positioned closely adjacent the abutment block 52, because of the small amount of fluid trapped between the abutment block 52 and the rotary piston 24, in the area around the roller 78, the vane 38 will be moved slightly toward the open position before it actually comes in contact with the abutment block 52. Thus, under normal operating conditions, the vanes 38 first contact the roller 78 which is journalled in the abutment block 52.

As the rotary piston 24 rotates and moves one of the vanes 38 into contact with the roller 78, the vane 38 starts to move toward the open position within notch As the vane 38 continues to swing toward the open position there is a squeezin action imparted upon the volume of liuid disposed within the notch 34. For the purpose of providing a means for the fluid to escape from within the notch 34, there is provided an oil slot or groove 112, see FIGURES 6 and 8 in particular.

It will be noted, when comparing FIGURES 5 and 6, that the vanes 38 are not diametrically spaced upon the rotary piston 24. The position of the swinging vanes 38 upon the rotary piston 24 is to be determined by the particular type of material used in the construction of the rotary piston 24- and swinging vanes 38. Since the casing 16, the front cover plate Zll, and the rotary piston 24 have no special requirement for construction from an extremely hard material, it is to be understood that they may be conveniently and more cheaply constructed of a material having qualities like those of aluminum. On the other hand, the abutment block 52 and the swinging vane 3:; do have functions which necessarily require them to be constructed of a hard, wear resistant material. Since such different materials would naturally have different specific gravities, the material removed to form notches 34 would necessarily not be equal to the weight of the material used to form the swinging vanes 38. Therefore, the position of the swinging vanes about the periphery of the rotary piston 24 is to be determined in such a manner so as to at least roughly balance the rotary piston 24 having a swinging vane 38 secured thereto. It is to be understood, that any final adjustment pertaining to the static or dynamic balancing of the rotary piston 24 may be achieved by the removal of small amounts of metal from either the notches 34 formed in the rotary piston 24 or any other convenient place which would not interfere with the operation of the fluid motor 10.

Thus it may be seen that herein is described a rotary piston fluid motor being constructed with a minimum number of moving. parts which has means to compensate for Wear occurring anywhere therethroughout, dynamic balancing for the rotary piston despite the provision of notches on its outer periphery having vanes pivotally mounted therein, and a means to secure more perfect exhausting of the work chamber by eliminating the development of back pressure as the vane passes the main exhaust port resulting in a fluid motor which Will require less maintenance and therefore one which will be more dependable.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A rotary piston fluid motor comprising a casing having a cylindrical chamber therein, a front cover plate for said cylindrical chamber, means removably securing said cover plate to said casing, a shaft journaled in said casing and said cover plate and extending through the latter, a rotary piston secured to said shaft and disposed centrally in said chamber, said piston being smaller than said cylindrical chamber and defining an annular work chamber therein, an abutment block disposed in said work chamber, fluid inlet and outlet openings through said casing and in communication with said work chamber each being on opposite sides of said abutment block and adjacent thereto, a plurality of spaced notches formed in the outer periphery of said piston, a plurality of vanes, means pivotally mounting one end of each vane in one of said notches, said vanes being entirely receivable therein when in their retracted position and having their free ends in sliding contact with the outer periphery cylindrical chamber, the contacting edges thereof being complementary when in their closed position, and said vanes then comprising piston heads for said rotary piston, said abutment block having a cam surface thereon adjacent said outlet opening and engageable by said vanes for moving the latter into their open or retracted positions, including an outwardly sealed bearing cap on the rear of said casing having a bearing therein for journalling the corresponding end of said shaft, and means for adjustably positioning said bearing cap outwardly on said casing whereby the clearance between said rotary piston and the rear of said casing may be adjusted as wear occurs therebetween.

2. A rotary piston fluid motor comprising a one piece casing having a cylindrical recess formed therein, a front cover plate for said recess, means removably securing said cover plate to said casing, a shaft journaled in said casing and said cover plate, a rotary piston secured to said shaft and disposed centrally in said recess, said piston being smaller than the cylindrical recess and defining an annular work chamber, an abutment block removably secured in said work chamber, fluid inlet and outlet lines communicating the exterior of said casing with said work chamber on opposite sides of said abutment block, a plurality of retractable vanes secured about the periphery of said piston, means for normally urging said vanes toward an extended position slidably engaging the outer periphery of said annular work chamber, said abutment block having a cam surface thereon on the approach surface engageable by said vanes for moving the latter into their retracted positions, an outwardly sealed bearing cap on the rear of said casing having a bearing therein for journaling the corresponding end of said shaft, and means for adjustably positioning said bearing cap outwardly of said casing whereby the clearance between said piston and the rear of said casing may be adjusted as wear occurs therebetween.

3. The combination of claim 2 including means for adjustably positioning said front cover plate inwardly on said casing whereby the clearance between said rotary piston and said casing may be adjusted as wear occurs therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 174,750 Waltner Mar. 14, 1876 587,904 Witts Aug. 10, 1897 625,799 Pickel et al. May 30, 1899 686,746 Macker Nov. 19, 1901 708,328 Eek et a1. Sept. 2, 1902 798,485 Augustine Aug. 29, 1905 800,633 Dengler Oct. 3, 1905 8 2,479 Hendrickson Oct. 2, 1906 833,588 Dabonville Oct. 16, 1906 869,397 Tippett et al. Oct. 29, 1907 992,582 Olson May 16, 1911 1,097,756 Hiester May 26, 1914 1,561,946 Rasmussen Nov. 17, 1925 1,953,029 Smith Mar. 27, 1934 2,189,088 Thompson Feb. 6, 1940 2,720,191 Vas Oct. 11, 1955 2,903,971 Collins Sept. 15, 1959 FOREIGN PATENTS 3,335 Great Britain 1810 5,004 Great Britain 1824 34,096 Sweden Jan. 25, 1912 OTHER REFERENCES A.P.C. application of Fries, Serial No. 316,982, published May 11, 194 

